What Happens If I Claim Exempt on One Paycheck?

If you claim exempt on one paycheck, your employer withholds no federal income tax from that check, so your take-home pay goes up by whatever would normally have been withheld for federal tax. Social Security and Medicare still come out. What happens after that depends on two things: whether you actually qualified to claim exempt under IRS rules, and how quickly you switch your W-4 back. For most people who do this once and then restore normal withholding, the consequence is a slightly larger tax bill (or smaller refund) at filing time, usually without penalties. For people who didn’t qualify and leave the exempt status in place, the cost climbs fast.

“One Paycheck” Isn’t a Setting on the W-4

The W-4 doesn’t work per paycheck. Once your employer processes an exempt W-4, exempt status applies to every paycheck until you submit a replacement. So getting a single paycheck with no federal withholding really means filing an exempt W-4, receiving one check under it, and then filing a new W-4 to put normal withholding back in place.

Your employer has some processing time. They must implement a new W-4 no later than the start of the first payroll period ending on or after 30 days from when they receive it.¹ That lag can stretch your “one paycheck” into two or three with no federal tax withheld, even if you turn in the corrected W-4 immediately. Plan on the possibility.

One more mechanical detail: an exempt W-4 is valid only for the calendar year in which you file it. To continue exempt status into the next year you must file a fresh W-4 by February 15. Miss that date and the employer reverts you to single with no adjustments.¹

Did You Actually Qualify?

Federal law sets two conditions, and both must be true when you sign the W-4. You had no federal income tax liability last year, meaning you were entitled to a refund of every dollar withheld. And you expect no federal income tax liability this year.² If either one fails, you don’t qualify, and the “exempt” claim is inaccurate.

In practice, this means your annual income has to stay low enough that the standard deduction wipes out your tax bill. For 2026, the standard deduction is $16,100 for single filers, $24,150 for heads of household, and $32,200 for married couples filing jointly.³ Full-time earnings well above those numbers almost certainly disqualify you. Refundable credits like the Earned Income Tax Credit can also drive liability to zero, but you need to work that out before claiming exempt, not after.

The Tax You’ll Owe at Filing

The federal tax your employer skipped doesn’t go away. You still owe it on the earnings from that pay period, and instead of paying it gradually through the year, you’ll owe it as part of your balance due when you file.

For a single paycheck, the number is usually manageable. On a $3,000 gross paycheck at roughly a 12% effective rate, the skipped withholding is around $360. Pay that when you file and you may face no penalty at all. The math changes if the exempt W-4 stayed in effect longer. Someone earning $75,000 a year who runs exempt for three months could face a surprise bill in the $3,000 to $5,000 range.

Interest runs on any unpaid balance from the return’s original due date until you pay in full. The IRS charges interest at the federal short-term rate plus three percentage points, compounded daily.⁴ Interest is rarely abated, even when a penalty is.

The Underpayment Penalty and Why One Paycheck Usually Escapes It

The penalty that most often applies to someone who underwithheld is the underpayment of estimated tax penalty under IRC 6654. It’s calculated as interest on each quarterly shortfall at the underpayment rate.⁵

You avoid it entirely by meeting any of these safe harbors:

You owe less than $1,000 when you file.
Your total withholding and estimated payments covered at least 90% of your current-year tax.
Your total withholding and estimated payments equaled at least 100% of last year’s tax (110% if your adjusted gross income exceeded $150,000, or $75,000 if married filing separately).⁶

The small-balance safe harbor is often the reason a one-paycheck exempt claim ends up penalty-free. If the skipped withholding was a few hundred dollars and normal withholding resumed on every other check, your balance due at filing may stay under $1,000 and the penalty never triggers.

There’s also a separate failure-to-pay penalty if you file but can’t pay the balance: 0.5% of the unpaid tax per month, capped at 25%.⁷ It runs alongside interest, so an unpaid balance grows on two tracks.

The $500 Penalty and the Criminal Statute

The IRS has penalties aimed specifically at false W-4 claims, and they escalate with intent.

The civil penalty is $500 per false statement on a W-4 that reduces withholding below what it should be, unless you had a reasonable basis for the claim when you made it.⁸ IRS Publication 505 notes that simple errors don’t result in this penalty, which suggests the agency applies it selectively rather than automatically.⁹ Someone who misread the eligibility rules and corrected the W-4 quickly is not the target. Someone who knowingly claimed exempt while earning a full salary is.

The criminal statute is 26 USC 7205, which covers anyone who willfully supplies false or fraudulent information on a W-4: a fine of up to $1,000, up to one year in prison, or both.¹⁰ Criminal prosecution for a single wrong W-4 is extremely rare and typically reserved for broader tax evasion patterns, but the statute is on the books.

How to Fix It

Fill out a new W-4 with accurate information and give it to your employer. They must put it into effect no later than the start of the first payroll period ending on or after 30 days from the date they receive it.¹

To figure out whether you need to catch up, use the IRS Tax Withholding Estimator, which walks through income, deductions, and credits and produces a pre-filled W-4 you can hand to payroll.¹¹ Line 4(c) lets you request an additional flat dollar amount withheld from each remaining paycheck, which is the simplest way to make up a gap.

Timing matters. Catching the shortfall in February gives you many paychecks to spread the catch-up across. Catching it in October squeezes the same makeup into far fewer checks. If the gap is too large to close through payroll alone, you can also send a quarterly estimated payment directly to the IRS using Form 1040-ES. Estimated payments are due April 15, June 15, September 15, and January 15 of the following year, and a well-timed lump sum can push you back inside one of the safe harbors and eliminate the underpayment penalty.

For someone who claimed exempt on one paycheck, corrected the W-4 promptly, and finished the year with a balance under $1,000, the realistic consequence is paying the extra tax at filing. That’s usually the whole story.

1
Internal Revenue Service. Topic No. 753, Form W-4 Employees Withholding Certificate
2
Office of the Law Revision Counsel. 26 USC 3402 – Income Tax Collected at Source
3
Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026
4
Internal Revenue Service. Topic No. 653, IRS Notices and Bills, Penalties and Interest Charges
5
Office of the Law Revision Counsel. 26 USC 6654 – Failure by Individual to Pay Estimated Income Tax
6
Internal Revenue Service. Underpayment of Estimated Tax by Individuals Penalty
7
Office of the Law Revision Counsel. 26 USC 6651 – Failure to File Tax Return or to Pay Tax
8
Office of the Law Revision Counsel. 26 USC 6682 – False Information With Respect to Withholding
9
Internal Revenue Service. Publication 505, Tax Withholding and Estimated Tax
10
Office of the Law Revision Counsel. 26 USC 7205 – Fraudulent Withholding Exemption Certificate or Failure to Supply Information
11
Internal Revenue Service. Tax Withholding Estimator